John a



@eine tetes @stent infirm JOHN A. LO'BB. OF INDEPENDENCE, MISSOURI.

Letters .Patent No. 77,824', dated May 12, A1868. 5

IMPROVEMENT IN I'GRUTGHES. Y

To ALLWHOM `IT MAY ooNoERN:

Y Be it known that I, .IOIIN IA. LOBB, of Independence, inthe county ofJackson, and State of Missouri, have invented a new and -improvedCrutch'; and I do hereby declare that the following is a full, clear,and exact description of the construction and operation of the same,reference being had to the accompanying drawings,

.and letters of reference marked thereon, making a part of thisspecification, of. which- Figure ll is a longitudinal vertical centralsection.

This'invention consists ot" an arrangement for imparting elasticity `toacrutch, to the end that it may bemore comfortable in use than thecommon rigid form, as will hereinafter more fully appear.

To enable those skilled in'the art to make and use my', invention, Iwillproceed to describe its construction and operation.'

A represents the stati' of a crutch, of wood or other vsuitablematerialnmade hollow for n. portion of' its length, from the top, sayone-third.` a represents a bar, attached to the hend-piece ',said barbeing made small enough to enter the'oriiice'in-"the staff A, and` beingitself hollow for a portionof its length, from thc bottom,

say, also, one-third. d. represents a plug, thel lower end of which isof similansize astlie'har a, for, say, one inch, while the upper portionissuiciently small to enter the orifice in the har a. A part, d', ofthis smaller portion, next the lower end d; is made suiiiciently largeto act as a stop, and is of a length corresponding to that of the.spiral spring, e, placed around the smaller portions of the plug d, andattached by clamps e' e,.rat its ends, to the plug dand the bar arespectively. f

It will be seen that, when the bar a, with the plug dand springeattached, is inserted in the oriiice of the` steif A, so far that theplug rests on the'bottom of the saidorifice, a yielding elastic supportis givento' the head-piece c, by means of which the jar incident to thestriking of au ordinarystati' upori the groundis materially abated.

The plug d insures the just action ofthe spring, preventing it-,fromreceiving damage, especially under pressure heavy enough to force .thelower'end of the bar a down into contac't with the stop d, as, when thisis done, the spring is wholly relieved from'strain. l v

The clamps e e are easilyadjusted, theirends being merely bent down atright angles, forming prongs.

i One prong of each clamp is inserted in a hole, made for the purpose`in thcwood, and the other placed over on of the convolutions of thespring. i

By giving the latter one or two turns, the clamp is firmly secured initsplace, and by turning the spring in the opposite direction, theclamp isloosened and'may be removed, whereupon the spring may also be removed.

Having thus fully described my invention, what I claim as new, anddesireto secure by Letters Patent, is-

1. The hollow steif A, in combination with-.the hollow bar. a the plugal, and'the spring e, substantially as and for the purpose set forth. 'y

2. The hollow bar a, in combination with the plug d, the spring e, andthe clamps elv c".

I JOHN A. LOBBL Witnesses:

O. P. W. BAILEY,

P. D. PoLLAnn.

